diff --git a/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java b/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
index 47452a11a..9c2c1a686 100644
--- a/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
+++ b/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
@@ -1445,7 +1445,6 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                 // from the server in order to drain it
                 if (unacknowledgedStanzas.size() == UNACKKNOWLEDGED_STANZAS_QUEUE_SIZE_HIGH_WATER_MARK) {
                     writer.write(AckRequest.INSTANCE.toXML().toString());
-                    writer.flush();
                 }
                 try {
                     // It is important the we put the stanza in the unacknowledged stanza